Bulk spreadsheet-based (most likely) method for uploading a lot of assets and write the user data in the asset when uploaded and create new users when necessary.
Flow may be something like:
- send
POST users with device_id = "firstname_lastname"
- response will include
user.id either newly created if doesn't exist or pre-existing based on device_id
- use
user.id in subsequent POST assets/ call to create new asset with proper user attached